1. Field
The present disclosure relates to zoom lens systems, imaging devices and cameras.
2. Description of the Related Art
Cameras including an image sensor for performing photoelectric conversion, such as digital still cameras and digital video cameras, have been required to have high resolution, and particularly in recent years, these cameras have been strongly required to have a reduced thickness, a relatively high zooming ratio, and capability of compensating various aberrations. For example, various kinds of zoom lens systems have been proposed, each having a three-or-more unit configuration of positive, negative, and positive, or positive, negative, and negative, in which a first lens unit having positive optical power, a second lens unit having negative optical power, a third lens unit having positive or negative optical power, and a subsequent lens unit are arranged in order from an object side to an image side. Hereinafter, the cameras including an image sensor for performing photoelectric conversion, such as digital still cameras and digital video cameras, are simply referred to as “digital cameras”.
Japanese Laid-Open Patent Publications Nos. 2009-282429, 2009-115875, 2009-086437, and 2008-304708 each disclose a zoom lens having the three-or-more unit configuration of positive, negative, and positive.
Japanese Laid-Open Patent Publication No. 2008-281927 discloses a variable-magnification optical system having the three-or-more unit configuration of positive, negative, and positive.
Japanese Laid-Open Patent Publication No. 2007-047538 discloses an imaging optical system having the three-or-more unit configuration of positive, negative, and positive, or positive, negative, and negative.
Japanese Laid-Open Patent Publication No. 2001-350093 discloses an imaging lens device equipped with a zoom lens system having the three-or-more unit configuration of positive, negative, and positive.